Analysis of non-destructive testing methods for assessing structural integrity in distressed building (Cases Study of Lagos Island, Lagos State, Nigeria)

The collapse of structures in urban areas is a growing concern that demands effective and reliable methods for assessing structural integrity. The urban landscape of Lagos Island, boasts a diverse array of buildings, but many face structural distress due to factors like age, environmental conditions, poor construction practices, posing risks to occupants and the community. This research assessed the effectiveness of various Non-Destructive Testing (NDT) techniques using Schmidt/Rebound Hammer test and Ultrasonic Pulse Velocity Testing to evaluate the structural integrity of Ten (10) distressed buildings on Lagos Island, taking into account local environmental conditions and construction practices. The outcome of this research shows that the Rebound Hammer and Pulse Velocity tests provides a comprehensive understanding of the material’s properties and quality. Likewise, the comparative analysis of the Rebound Hammer and Pulse Velocity tests shows that both methods offer valuable insights into the quality and integrity of concrete structures with the Pulse Velocity test showing a slightly higher consistency in results. The Rebound Hammer method readings were averagely higher by 5N/m² to Pulse Velocity test readings. Therefore, Pulse Velocity test is more consistence, detects internal structural defects like cracks, voids and honeycombs homogeneity than Rebound Hammer method.